Lichen planus is a chronic mucocutaneous inflammatory disease aff ecting 1-2% of the general population with maximum prevalence of the disease in women above the age of 40. Its aetiology remains unclear and the pathogenesis is still the object of much speculation. It is considered to be an autoimmune disorder mediated mainly by the T-lymphocytes. The present paper presents the most well-known external agents (viruses in particular), internal agents like stress, and the heat shock protein thought to be trigger factors and describes the action of diff erent cells and proteins associated with the development of that disease. Diagnosis is based on clinical and histopathologic evidence; direct and indirect immunofluorescence techniques can also be of use. Despite the wide variety of therapeutic modalities, treatment outcomes are often insufficient. Currently, topical corticosteroids are widely accepted as a standard therapy, but also retinoids, calcineurin inhibitors and other immunosuppressants can be administered. Because of the aspect relevant to these drugs, priority is given to alternative harmless methods such as LLLT and PDLT. There is an ongoing controversy in the literature about the possible premalignant character of oral lichen planus, however, periodic followup is recommended.

Background: The erosive-atrophic form of oral lichen planus (OLP) is associated with severe pain and burning sensation and is often unresponsive to treatment. Topical corticosteroids are considered as a medication of first choice but they can produce adverse effects. Therefore, new therapeutic approaches are required. Aim: The aim of this study was to investigate the effectiveness of biomodulation with diode laser in patients presenting with long-standing erosive-atrophic OLP. Materials and methods: Twelve patients, clinically and histologically diagnosed with OLP, participated in this study. The level of pain and the clinical scores of total 59 lesions were recorded before treatment using visual analog scale and Thongprasom sign scoring system respectively. All patients received low level laser therapy (LLLT) with diode laser (810 nm) with parameters (0.5 W, 30 s, 1.2 J/cm²) three times weekly for a month. The response rate was assessed according to the decrease in pain and sign scores. Treatment efficacy index was calculated. Results: There was a significant reduction in pain after LLLT (p<0.0001). Improvement in clinical signs was achieved in 59.3% of the lesions. At the end of the treatment 5.1% of the lesions exhibited score 5; 6.8% - score 4, 11.9% of the lesions were scored 3 and 8.5% and 30.5% showed score 2 and score 1, respectively. Complete resolution was revealed in 37.3% of the lesions. All patients experienced some degree of improvement. Most of the cases showed moderate recovery. Conclusion: The present results indicate that LLLT is an effective and harmless modality for management of erosive-atrophic OLP.

Aim: The present clinical study aimed to investigate the clinical efficacy of 5 types of mouthwash based on different active substances. Materials and methods: The study included 180 patients divided into 6 groups of 30 patients, each group rinsing with one of the following types of mouthwash based on: essential oils, combination of essential oils and 0.12% chlorhexidine, hydrogen peroxide (0.8%), prebiotic, 0.2% chlorhexidine, and placebo. All participants underwent professional mechanical plaque removal after which they were instructed to rinse with 15 ml mouthwash 2 times a day for 21 days. During the study period, patients were monitored at days 0, 14, and 21, examining oral hygiene index, gingival index, bleeding index, and presence of side effects. Results: Gingival index, bleeding index, and oral hygiene index were reduced statistically significantly in all treatment groups. Adjunctive use of mouthwashes demonstrated better clinical effectiveness compared to mechanical plaque control (and placebo mouthwash). The gingival index and the plaque index were reduced most significantly in the group using mouthwash with hydrogen peroxide. The bleeding index decrease was most significant in the group using 0.2% chlorhexidine. Conclusions: All tested mouthwashes demonstrated significant clinical effectiveness in different degrees in gingivitis treatment. New formulas with prebiotic and combination of essential oils and chlorhexidine indicate promising effectiveness.

Oral lichen planus (OLP) is a chronic inflammatory disease, in which T-Lymphocytes induce apoptosis of basal keratinocytes, leading to the formation of symptomatic lesions. It is assumed that blocking the cell death program and enhancing cell proliferation would be crucial to the healing process. The aim of the study was to verify the efficacy of Photobiomodulation (PBM) in OLP management, by evaluating the effects of laser irradiation on the processes of apoptosis and cell proliferation. Twenty patients with OLP underwent PBM with 810 nm diode laser (0.5 W, 30 s, 1.2 J/cm²), 3 times a week for one month. The size and clinical scores of the lesions and pain level were recorded and compared before and after therapy using Thongprasom sign scoring system and Visual Analogue Scale, respectively. Biopsies were taken before and after therapy and analyzed immunohistochemically for bcl-2 and Ki-67 expression. Tissue sections from 10 healthy volunteers were used as controls for the levels of these markers in normal oral mucosa. PBM significantly reduced patients' pain intesity and improved the clinical signs of the lesions. OLP tissue sections demonstrated lower staining for bcl-2 and Ki-67 compared to healthy controls. After therapy the expression of bcl-2 increased significantly. An enhance in Ki-67 immunoreactivity was revealed predominantly in the atrophic-erosive epithelium. PBM is an effective treatment modality for OLP patients. Erosive forms of the disease responded better to laser irradiation than keratotic subtypes. At the molecular level, PBM is likely to recover the impaired cell cycle mechanisms and keratinocyte proliferation.

Background/Objectives: The diagnosis of oral lichen planus (OLP) is challenging because many other oral diseases demonstrate similar clinical and microscopic features. Clinicopathological discrepancy and inter- and intraobserver variability in the histological assessment of OLP have been shown in the literature, as there are no unified diagnostic criteria for the disease. In 2016, the American Academy of Oral and Maxillofacial Pathology (AAOMP) proposed a new diagnostic set for OLP. The aim of the study was to assess the reliability of the AAOMP histological criteria in diagnosing OLP. Methods: In this retrospective study, 34 histological sections, once diagnosed as OLP, were revised by a second pathologist using the WHO criteria. Then, all specimens were analyzed for the presence (P) or absence (A) of the criteria listed in the AAOMP diagnostic set. The reproducibility of the histological diagnosis of OLP when applying the different sets of diagnostic criteria was assessed. Results: From the AAOMP diagnostic criteria, hydropic degeneration was found in 35.2%, lymphocytic exocytosis in 32.3%, mild epithelial dysplasia in 2.9%, verrucous epithelial architectural change in 0% and band-like lymphocytic infiltrate, confined to the epithelium-lamina propria interface in 55.8% of the samples. Reproducibility of the histological diagnosis of OLP was achieved in only 19.3% of the cases when applying the 1978 WHO criteria versus the newly proposed AAOMP criteria. Conclusions: A large number of OLP cases failed to meet the AAOMP histological criteria in the present study. Further studies are needed to assess the validity of the proposed diagnostic set.

Background: Oral lichen planus (OLP) is a mucocutaneous disease associated with the formation of symptomatic lesions in the mouth that are often refractory to treatment. An as-yet-unknown antigen triggers an inflammatory reaction in which various immune and non-immune cells release multiple cytokines that contribute to disease progression. The ability of photobiomodulation (PBM) to reduce the symptoms and signs of the disease has been shown, but little is known about its molecular and cellular effects. The aim of this study was to evaluate changes in pro-inflammatory cytokine levels and in histological findings in OLP patients treated with photobiomodulation therapy. Methods: Twenty OLP patients underwent PBM with diode laser (810 nm), (0.50 W, 30 s, 1.2 J/cm²), 3 times weekly for a month. Pain level and clinical scores of lesions were recorded before and after therapy. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were measured before and after PBM and compared with those of 10 healthy controls. Biopsies were taken at the beginning and end of treatment to assess pathomorphological changes. Results: PBM significantly reduced the level of pain and clinical scores of the lesions. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were significantly higher compared to those in healthy controls and decreased after therapy. 60% of the post-treatment OLP biopsies demonstrated histological improvement, characterized by inflammatory infiltrate reduction (50%), epithelial hyperplasia reduction (30%), epithelial thickening (15%), or epidermal-dermal attachment repair (5%). Conclusion: The effectiveness of PBM therapy in OLP patients was confirmed at the clinical, molecular, and histomorphological levels.